Testing-machine



H. L. SCOTT.

TESTING MACHINE.

APPLICATION FILED APR.21.19|7.

1,372,093, Patented Mar. 22, 1921.

2 SHEETS-SHEET l.

H. l.. SCOTT.

TESTING MACHINE.

APPLmATloN HLED APR.21,1`911.

15b-5372,09 3. Patented Mar. 22, 1921.

1 l 2 SHEETS-SHEET 2.

. M-- Zo Qi( 2f l T r 28 UNITED STATES HENRY L. SCOTT, OE PROVIDENCE,RHODE ISLAND. i

TESTING-MAGHINE Specification of Letters Patent. Patented Mall'. 22,1921;

Application filed April 21, 1917. SerialNo. 163,553.

To all whom t may concern.'

Be it known thatI HENRY L. Soo'r'r, a citizen of the United States, andresidentof the city of Providence, in the county of Providence and Stateof Rhode Island, have invented certain new and useful Improvements inTesting-Machines, of which the following is a specification.

This invention relatesto switch operating mechanism for testing machinesforautomatically controlling the action of the driving motor, and theobject of this invention is to provide in such a machine simple andeffective means for reversing the direction of travel of the tensionmechanism at the end of its operating stroke. Y

The invention further consists in providing means for automaticallystopping the motor if desiredwhen the tension mechanism has completed adownward stroke and returned to the starting point.

With these and other objects in view, the invention consists of certainnovel features of construction, as will be more fully described, andparticularly pointed out in the appended claims.

In the accompanying drawings:

Figure l-is a side elevation of the clamp operating mechanism.

F ig. 2-is an end view on a larger scale sectioned on line 2.-2 of Fig.1 showing the arrangement of mechanismv through which the electricswitch is operated.

Fig. 3-is a face view of the switch having start, reverse and stopterminals.

Fig. .f--is a face View of a switch having start and reverse terminalsonly. y

Fig. --is an outline of a knife switch which may be inserted in the mainline for starting the motor.

Referring to the drawings, 10 designates the screw shaft member which isconnected to the lower clamp 11 and through which tension is applied tothe goods 12. This screw threaded shaft is provided with an operatingnut 13 working between the end bearings 14 and 15. This nut is shown asbeing provided with a worm gear, which is rotated by means of a worm 17mounted on the shaft 18 on the electric motor 19 whereby the action ofthis motor causes the nut to rotate and so provide an endwise motion tothe screw.

In order to control the action of this motor, I have provided anelectric switch 20, a simple form of which is Shown as being connectedtothe motor through the wires 21. This switch is` provided` with aswitch bar 22-adapted to be rotated through its center spindle 23 tocomplete the circuit th-rough the various contact points. For instancewhen the bar is in the position shown in Fig. 3 the circuit is broken tostop the motor; when moved to engage contact 25 it completes the circuitto the motor and `rotates the same in one direction; when moved tocontact 26 it reverses the current through themotor and drives the motorin the opposite direction, and when moved to contact 27 the; circuit isagain broken.

This switch may be operated by hand through the handle 28 to the firstposition and then be operated automatically through the action of theoperating mechanism to the other two positions or it may be operatedentirely by hand if desired. p

To` accomplish this automatic action in a simple and practical way, Thave providedtwo endwise slidable racks 29 and 30 movably mounted in theframe 31, and have provided a short shaft 32, one end of which isconnected to the switch operating shaft 23 and on this short shaft ismounted al gear 33 which engages rack 30 and gear 34 which mesh with thepinion 35, which in turn engages raclr 29. These two gears 34 and 33 arefconnected together to rotate freelyon shaft 32, gear 33 being mountedupon and fixed to the hub of geari.

A ratchet wheel 36 is connected by a set screw 37 to this short shaft 32and is en.- gaged by a pawl 38 mounted on the gear 33, whereby adownward movement of rack 29 acting through its pinion gear serves torotate the switch in a clock-wise direction through the said pawl andratchet and it will be also seen that by a direct connection between therack 30 and the gear 33 that an upward movement of this rack also movesthe switch in a clock-wise direction through the same pawl and ratchetwheel but at a greater rate of speed, and that a movement of one rackmoves the other in the opposite direction.

The operation of the device is as follows z--To start the motor it isnecessary to throw the switch by hand from point 27 to point 25. Themotor is thus energized and the tension screw moved downward until thearm 39 which is fixed thereon engages and moves the rack 29 in the samedirection. This action throws the switch from contact 25 to contact 26,thereby reversing the direction of the current andthe direction orotation of the motor, which action serves to return the screw to itsraised or normal position. As soon as released the racks are bothreturned to'normal by spring 4l that is rack 24 to its raised and rack30 to its lower position, but owing to the diierence in the gearing theytravel at diierent speeds `and each with a diiferent length of stroke,the action of both, however, upon-the switch is to advance it'one stepat each action.

When the Screw approaches its up position its lower arm 40 engages therack 30 which has now been positioned to receive it and through themechanism above described rota-tes the switch onto thepoint 27, whichautomatically stops further action of the motor until again started bythe hand of the operator.

I have shown and described a switch wherebyits movement by the hand ofthe operator starts the motor and after the motor Vhas completed acycle, which is a movement of the screwy Afirst downward and thenupward, the motor is automatically stopped, butin some cases such asapplying what is known as the-fatigue test to a strip of elasticmaterial, which is that of seeing how many times this material can bestretched a given amount before breaking, it is found desirable toprovide a switch mechanism which will cause the motor to automaticallyreverse at the upper, as well as at the lower end of its stroke, and socontinueto reciprocate until stopped by the hand of the operator. A

To accomplish this, I have provided a switch such as that illustrated inFig. 4 which has two contacts 42 and 43, when the switch bar 22 is on 42the motor is caused to run in one direction and when on 43 the motor iscaused to run in the opposite direction, the circuit being completed andbroken in the main line Vby means of a hand switch such as illustratedin Fig. 5.Y

lThe foregoing description is, of course,

directed solely toward the construction illustrated, but the device issusceptible of modifications, the invention not being limited in anyother way than by the terms of the appended claims.

I claim:

l. In a testing machine, a screw through which tension is applied forthe test, an operating nut on said Screw, an electric motor mounted torotate said nut to impart an endwise motion to said screw, an electricswitch, and a switch operating member actuated by the movement of saidscrew at the end of one stroke thereof to throw said switch to at oncereverse the action ot said motor and at the end of its opposite stroketo stop said motor.

2. In a testing machine, a screw through which tension is applied forthe test, an electric motor for operating said screw, and meansincluding pawl and ratchet mechanism arranged to be actuated by themovement of said screw for operating said switch to control the actionoi said motor.

3. In a testing' machine, a screw through which tension is applied forthe test, an electric motor for operating the screw, an electric switch,and means including a pair of reciprocating racks actuated by themovement of said screw for operating said switch to control the actionof said motor.

4. In a testing machine, a screw through which tension is applied to thegoods, an electric motor for operating said screw, an electric switch,pawl and ratchet mechanism through which said switch is rotated, a pairof reciprocating racks through which said ratchet is operated, and meanson said screw for engaging and moving said racks at opposite ends of itsstrokes whereby the operation of said motor is controlled.

In testimony whereof I affix my signature in presence of a witness.

HENRY L. SCOTT.

Witness HOWARD E. BARLow.

